March 2006 - Boost-users - lists.preview.boost.org

Re: [Boost-users] FW: adjacency_list remove_edge
by Sean Kelly 10 Apr '06

10 Apr '06

Hi Doug, here is the example code that works - XFlatGraph is a listS, listS adjacency_list. Note if I replace the remove edge expression with remove_edge(*iter, _graph) the edge is intermittently not removed thanks Sean XFlatGraph& graph = _flat_view->get_graph(); XFlatEdgePMap& edge_pmap = get(kFlatGraphEdgeProperty, graph); std::list<XFlatView::edge_descriptor> scheduled_for_removal; XFlatView::edge_iterator current, end; tie(current, end) = edges(graph); for(;current!=end;++current) { if(edge_pmap[*current]->get_impl()->isSimulationOnly()) { scheduled_for_removal.push_back(*current); } } // Remove edges marked as simualtion only scheduled_for_removal.unique(); for(std::list<XFlatView::edge_descriptor>::iterator iter = scheduled_for_removal.begin(); iter != scheduled_for_removal.end(); ++iter) { remove_edge(source(*iter, graph), target(*iter,graph), graph); } System Information: compiler info: Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.3077 for 80x86 Copyright (C) Microsoft Corporation 1984-2002. All rights reserved. Boost version 1-32 -----Original Message----- From: boost-users-bounces(a)lists.boost.org [ mailto:boost-users-bounces@lists.boost.org] On Behalf Of Doug Gregor Sent: Thursday, March 02, 2006 12:42 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] FW: adjacency_list remove_edge On Mar 1, 2006, at 6:33 PM, Sean Kelly wrote: > I have observed the following behavior using the remove_edge function > and am curious if anyone else has seen this. > > remove_edge(edge_descriptor, graph) // occasionally fails in a > seemingly indeterminant way > > remove_edge(source(edge_descriptor, graph), > target(edge_descriptor, graph), > graph) // works fine It sounds like either the edge_descriptor is getting invalidated or there is a bug somewhere in remove_edge. > The adjacency list I am using is listS listS, and this is not an issue > with invalid edge_iterators, i.e. I collect all the edge_descriptors > to be removed before removing them. Are you sure that there are no duplicate edge descriptors? > I can provide more detailed info upon request. We won't be able to help without more detailed information. Doug _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Shortest Path City map
by Jeroen Vanattenhoven 10 Apr '06

10 Apr '06

Hello, I'm just learning and reading about the graph theory and shortest path algorithms. For graph representation there are 3 possibilities: adjacency matrix for dense graphs, adjacency lists for sparse graphs and edge lists. The road network of a city map belongs to which category? I've also been reading that Dijkstra is applied to a directed graph. Calculating the shortest route in a city map implies an undirected graph (am I wrong?). So how can I do shortest path calculation of a city map the best way? Jeroen

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[Multi_Array] distiontion be tween views, array_view, sub_array_view etc.
by Robert Ramey 06 Apr '06

06 Apr '06

The multi_array library seems to a good fit for a situation which I'm currently dealing with. I'm having a lot of problems understanding how to use it though. I can't really understand the distinction between the differing types of views, subviews etc. I would sort of expect that a new instance of a multi_array could be created by passing a reference to anything that fullills he requirements of a multi_array. That seems not to be the case. If you could pont me to any additional information on this library, I would be interested. Robert Ramey

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using random library
by Kamil Renczewski 04 Apr '06

04 Apr '06

Hello I have a problem. I need to write program, whitch interprets arguments given at runtime and create generators from this arguments. Then i have to use this generators (by calling operator() method) to generate numbers. Problem is that i dont know type of generators at compile time and i dont know how to store them in struct or class or even pass to a function. Here is en example of my thinking: i run program like this: generators N 10 2 E 2.3 and i would like to get some ramdom numbers from a normal_distribution<>(10, 2) and exponential_distribution<>(2.3) another run of a program might be: generators U -10 30 G 0.3 whitch should give me an uniform_int<>(-10, 30) and geometric_distribution<>(0.3) . Any ideas how to do this? thanks

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boost::bind to member variables
by Nico Galoppo 03 Apr '06

03 Apr '06

Hi, what kind of object does boost::bind return when binding to a class member variable ? (as opposed to a member method). Is it a function object too? More in particular, I would like to write a generic free function that applies an operation on a particular member variable, passed in with boost::bind. Something like this: struct A { int value; }; void f(bind_return_type& membervar) { membervar = 3; } A a; f(bind(&A::value, a)); Thanks. --nico -- nico galoppo von borries | address: 105 creel st., chapel hill comp. graphics phd. student | north carolina, 27516 USA UNC, chapel hill | phone: +1 (919) 962-1898 (office) | +1 (919) 942-7609 (home) | email: nico at cs dot unc dot edu | homepage: http://www.ngaloppo.org

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[serialization]problem with tree-structure
by heinz meier 01 Apr '06

01 Apr '06

Hello! I want to serialize a self made tree-data-structure. It consists of nodes which are conected via pointers to other nodes. I can serialize an object that contains only one of these nodes. But when i connect other nodes via pointers to that node i get a segmentation fault when i try to serialize that. I read the "Serializable Concept" in the Reference that says that it should work and i assume that i implemented the serialization-libary correct, because it works for a single node... I have no idea what can be wrong. So can someone help me please? I'm using the "libboost_serialization-gcc-1_33_1" libary and gcc 3.3.5 -- E-Mails und Internet immer und �berall! 1&1 PocketWeb, perfekt mit GMX: http://www.gmx.net/de/go/pocketweb

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Serialization creates huge object file
by Zoltan Szatmary 31 Mar '06

31 Mar '06

Dear Robert, I have been using the serialization lib for a while. I already wrote some mail to this list as you might remember. I was quite satisfied with its performance and ease of use, but now there is a problem I cannot solve. I need to serialize/deserialize some 50 polymorphic classes, so I do BOOST_CLASS_EXPORT them. I put all the serialization related logic into one definition (.cpp) file. I only use two types of archives, xml_iarchive and xml_oarchive. Now, when I compile the file with Intel compiler v8.2 on an Itanium based machine and with debug info the result is a huge (>42MB) object file, which ld (the linker) simply refuses to link. I am quite sure that the size of the object file is the problem. I tried to separate the xml_iarchive related code to one .cpp file and the xml_oarchive related code to an another, but of course this means that export.hpp is included to both, which results in multiple definitions error when trying to link the two object files together. Could you suggest any solution? Thank you very much in advance Zoltan Szatmary

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Re: [Boost-users] Problems compiling Serialisation libs because o f Spirit problem
by James Hughes 31 Mar '06

31 Mar '06

Hi Joel. > -----Original Message----- > From: Joel de Guzman [mailto:joel@boost-consulting.com] > Sent: 30 March 2006 23:43 > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Problems compiling Serialisation > libs because > o f Spirit problem > > > > The spirit list is the proper venue for spirit related questions. > spirit-general(a)lists.sourceforge.net. Will try there. > > Anyway... I am not sure what the workaround is here. I do not > have access to g++3.4.3. We've tested against all versions of > g++ (including 2.95.3 for Spirit 1.6.x) and I don't recall > any problems. I am currently testing against 3.4.4 and I see > no problems. Do you have a minimal cpp test file I can try? > Perhaps posting the compiler errors might help. One of the errors (all errors seem to relate to this one area) was included in the previous post on the subject, but it is just a build of boost, without any of my code anywhere near! Not sure an example is necessary, it's all boost library code. I am thinking it must be something to do with cross compiling (x86 host compiling to ARM code), but cannot see why it should be. My (previously limited) template understanding is improving rapidly, trying to figure out how this stuff works! James

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Re: [Boost-users] Problems compiling Serialisation libs because o f Spirit problem
by James Hughes 30 Mar '06

30 Mar '06

Some more information on this... Looking at the headers that give the error, there appears to be an issue with the result types returned from parsers.... boost/spirit/core/parser.hpp template <typename DerivedT> struct parser { typedef DerivedT embed_t; typedef DerivedT derived_t; typedef plain_parser_category parser_category_t; template <typename ScannerT> struct result { typedef typename match_result<ScannerT, nil_t>::type type; }; boost/spirit/core/primitives/numerics.hpp struct sign_parser : public parser<sign_parser> { typedef sign_parser self_t; template <typename ScannerT> struct result { typedef typename match_result<ScannerT, bool>::type type; }; The derived sign_parser class appears to want to 'override' the base class struct result, but instead the compiler is giving an error. This would appear to be a compiler fault, but I could be way off there - depends whether this compiles in other circumstances!! I am still at loss to fix this so all help gratefully received! James > -----Original Message----- > From: James Hughes [mailto:JHughes@Linx.co.uk] > Sent: 30 March 2006 11:34 > To: 'boost-users(a)lists.boost.org' > Subject: [Boost-users] Problems compiling Serialisation libs > because of > Spirit problem > > > Hello all, > > I reported some time ago an issue with trying to compile the > Boost libs > using an ARM cross compiler. > > This has just started to have an impact as I wish to try out the > Serialisation libs, and these are one of the areas with a > compile issue. > > The following error is repeated over a considerable number of > files and > seems to indicate a problem with Spirit. > > I am using the latest release version of Boost (1.33.1)- no > patches (are > there any?) and a gcc v3.4.3 cross compiler to ARM architecture. > > Does anyone have any suggestions? I have had no luck figuring > it out, but to > be honest haven't spent a lot of time on it yet. > > Rgds > > James

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portable uuid generator
by Tim Blechmann 30 Mar '06

30 Mar '06

hi all, working on a crossplatform program at the moment, i'm in need of a portable uuid generator ... currently, i'm using libuuid on linux and i read through the msdn about generating gid, but if there's a uuid class (maybe in boost?) that already does it, it would handy ... thanks ... tim -- TimBlechmann(a)gmx.de ICQ: 96771783 http://www.mokabar.tk You can play a shoestring if you're sincere John Coltrane

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